Closure cap

ABSTRACT

A closure cap for a container containing carbonated beverages has a head plate ( 2 ) and a substantially cylindrical cap skirt ( 4 ) extending from the edge ( 3 ) of the head plate ( 2 ). A cap thread ( 6 ) is provided on the inside ( 5 ) of the cap skirt ( 4 ). In the transition region ( 7 ) between the head plate ( 2 ) and the cap skirt ( 4 ) reinforcing ribs ( 8 ) are provided, which extend up to the head plate ( 2 ).

This application is the US national phase of international applicationPCT/GB00/04179 filed 1 Nov. 2000, which designated the US.PCT/GB00/04179 claims priority to EPO Application No. 99122306.6, filed8 Nov. 1999. The entire contents of these applications are incorporatedherein by reference.

BACKGROUND OF THE INVENTION

The invention concerns a closure cap, in particular a closure cap for acontainer containing carbonated beverages.

A large number of different embodiments of screw closure caps made ofplastics material are used today for the closing of containers, such ase.g. beverage bottles.

The final position, when the closure cap is in its fully screwed-onstate, is determined on the one hand by the screwing-on, twisting momentand on the other hand, by the relationship between geometry of theclosure cap and the container mouth. In particular, in the case ofclosure caps with internal lip seals, the final position of the closurecap is reached, when the inside of the cap top plate rests against thefront side of the container mouth in the manner of a stop.

One problem with such known closure caps consists in so-calledoverturning. If a user mistakenly tries to twist a mounted closure inthe wrong direction using force (i.e. continuing to screw-on instead ofunscrewing) there is a danger that the threads of the closure cap maysnap over the threads of the container mouth. Thus, the closure cap maytemporarily become disengaged from the container mouth. In particular,in the case of bottles with contents held under pressure, such ascarbonated beverages for example, there is a danger that at the sametime, the closure may fly off the bottle i.e. missiling. Such missilingcan injure the user.

Overturing safeguards have already been suggested, which prevent suchoverturning or in the event of overturning lead to a controlled gasblow-off. In WO95/21095 a braking element is described, which isarranged outside the thread path used to mount the closure and which, inthe event of attempted overturning, engages with the thread of thecontainer mouth. Overturning is thereby avoided.

This solution has the disadvantage that the closure cap is greatlydeformed in the radial direction in the event of overturning.

Braking elements are also known, which define the end of the screwing-onprocess; thus from WO 90/10581 a braking element acting in the axialdirection or in the circumferential direction is known, which towardsthe end of the screwing-on process engages with the start of the threadof the container mouth and so limits the screwing-on process.

SUMMARY OF THE INVENTION

An aim of the present invention is to avoid the disadvantages of theknown overturn protection arrangements. In particular, an aim of theinvention is to create a closure cap, which effectively preventsoverturning when the closure cap is mounted on the container mouth andat the same time effectively prevents deformation of the cap in theevent of an attempt at overturning. The closure cap according to theinvention, may be produced easily and can be used on conventionalclosure mouths.

As in conventional closure caps, the closure cap consists of a headplate and a more or less cylindrical cap skirt, which extends from theedge of the head plate. On the inside of the cap skirt a thread isprovided, which can be brought into engagement with a complimentarythread on the container mouth.

In the transition zone between the head plate and the cap skirt,reinforcing ribs, which extend up to the head plate, are arranged on theinside of the cap skirt. In the case of a closure-cap-having an outerseal arranged in the transition zone between cap skirt and head plate,the reinforcing ribs can only extend below the outer seal.

The closure cap according to the invention has no additional brakingelements, which limit the screwing-on movement. The end of thescrewing-on movement is therefore determined by the fact that the insideof the head plate rests against the front side of the container mouth.

The reinforcing ribs between the head plate and the cap skirteffectively counteract the overturning of the closure cap, even whenincreased force is applied. The reinforcing ribs stiffen the cap skirtand head plate in the transition zone, so that radial bulging of the capskirt or excessive spreading between the head plate and cap skirt isavoided.

According to a preferred embodiment of the invention, the reinforcingribs are arranged in an area towards the head plate-side of the capthread, as seen in the circumferential direction.

Advantageously, the reinforcing ribs extend in the axial directiondownwards at least as far as an imaginary screwing line, whichcorresponds more or less to the continuation of the cap thread. Thereinforcing ribs thereby form an extension of the cap thread.

Where the reinforcing ribs extend below the imaginary screwing line, abraking effect and an additional overturning safeguard is produced atthe end of the screwing-on process.

Advantageously, the reinforcing ribs extend more or less around anangular sector of 90°, which seen in the circumferential direction liesnext to the end of the cap thread.

In a further preferred embodiment additional, second reinforcing ribscan be provided in the transition region between head plate and capskirt. These second reinforcing ribs are arranged outside the angularsector over which the reinforcing ribs extend. The length of the secondreinforcing ribs in the axial direction is more or less equal. Thesecond reinforcing ribs thus have a stiffening function and do not formany continuation of the cap thread. The second reinforcing ribsmoreover, run on and so likewise limit the screwing-on movement.

The reinforcing ribs and/or the second reinforcing ribs advantageouslyextend sufficiently inwards in the radial direction that their innerfaces lie on an imaginary cylindrical section. The imaginary cylindricalsection essentially corresponds to more or less the cylindrical outerface of the container mouth. In this way, the reinforcing ribs (and ifnecessary the second reinforcing ribs) additionally have a centringeffect.

The reinforcing ribs are particularly advantageous, where the closurecap is provided with a stop face on the inside of the head plate, whichengages with the front side of the container mouth when the closure capis mounted on the container. In this way, the screwing-on position isdefined exactly. Forces acting on the head plate, which would normallyresult in a deformation of the head plate, are directed into the capwall through the reinforcing ribs. Because of the reduced deformabilityof the head plate, the reinforcing ribs give both an exactly defined endposition of the closure cap and also an overturning safeguard. Inaddition, an overturn safeguard such as that described in WO 095/2105can be used particularly advantageously. In this arrangement, thereinforcing ribs are arranged opposite the braking element e.g. two setsof reinforcing ribs can be provided. The content of WO 95/21095 isexpressly incorporated by reference in the present application.

The invention is described below in more detail by means of exampleembodiments explained by means of the drawings. They show:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 a cross section through a closure cap according to the inventionalong the plane A—A indicated in FIG. 4,

FIG. 2 a schematic perspective representation of a cut-open closure capmounted on a container mouth,

FIG. 3 an enlarged representation of the transition zone between headplate and cap skirt of a closure cap according to the invention mountedon a container mouth,

FIG. 4 an underneath view of the closure cap according to the invention,

FIG. 5 an enlarged representation of the cut-out section C from FIG. 4,

FIGS. 6 a and 6 b schematic representations of further embodiments ofthe invention, and

FIG. 7 a schematic representation of an embodiment with an outer seal.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In FIG. 1 a closure cap 1 is shown in cross section. The closure cap 1has a head plate 2. From the edge 3 of the head plate 2 extends asubstantially cylindrical cap skirt 4. The cap skirt 4 is provided onits inside 5 with a cap thread 6. The cap thread 6 is used for screwingthe closure cap 1 on to a container mouth 21 having a mouth thread 26(see FIG. 2).

The closure cap 1 is provided with a conventional inner seal 12. Theclosure cap 1 may also have a guarantee band 14.

On the inside of the head plate 2 is a stop 13, which comes intoengagement with the front side 23 of the container mouth 21 (see FIG. 3)when closure cap 1 is mounted on the container.

In the transition zone 7, between the head plate 2 and the cap skirt 4,reinforcing ribs 8 are provided on the inside 5. The reinforcing ribs 8extend in the axial direction up to the head plate 2 and up to the stop13 respectively. The reinforcing ribs 8 stiffen the head plate 2 and thecap skirt 4 in the transition zone 7. Because of this stiffening,overturning of the closure cap is avoided.

The reinforcing ribs 8 are arranged in a region 9, which lies next tothe end 10 of the cap thread 6, when viewed in the circumferentialdirection. The term the end of the thread is used here, and below, todescribe the head plate-side end 10 of the cap thread 6.

The length 1 of the reinforcing ribs 8 has been chosen so that the loweredge 15 of the reinforcing ribs 8 follow an imaginary screwing line S,which forms an extension of the cap thread 6.

FIG. 2 is shows a perspective representation of a cut-open closure cap 1mounted on a container mouth 21. The same reference symbols as used inFIG. 1 denote the same parts.

FIG. 2 shows that the reinforcing ribs 8 form an extension of the screwthread 6 of the closure cap 2 and follow the mouth thread 26 of thecontainer mouth 21.

Moreover, in the right half of FIG. 2 second reinforcing ribs 18 areshown, which extend over a circumferential area of somewhat less than180° and which are arranged diametrically opposite the reinforcing ribs8. The second reinforcing ribs 18 are all of equal length l′. The secondreinforcing ribs 18 have only a stiffening function and form noextension of the cap thread 6 of the closure cap 1.

FIG. 3 shows an enlarged representation of a cross section through acut-out of the closure cap 1 in the transition zone 7.

The closure cap 1 is in the screwed-on position. The stop 13 restsagainst the front side 23 of the container mouth 21. The reinforcingribs 8 each have a different length 1. The length 1 has been chosen sothat with closure cap screwed on (i.e. with abutment of the front side23 on the stop 13) the lower edge 15 of the reinforcing ribs 8 liesagainst the mouth thread 26. In FIG. 3 the stiffening effect of thereinforcing ribs 8 is clear. When the stop 13 lies against the frontface 23, a further twisting of the closure cap 1 is avoided, because thehead plate 2 cannot move in relation to the cap skirt 4.

The reinforcing ribs 8 also have a centring function. The reinforcingribs 8 extend inwardly in the radial direction r, such that their innerface 11 lies on an imaginary cylindrical cut-out Z. The cylindricalcut-out Z corresponds more or less to the cylindrical face Z, which isdefined by the container mouth 21.

FIG. 4 shows an underneath view of the closure cap of FIG. 1. FIG. 1corresponds to a section along the plane A—A in FIG. 4. According toFIG. 4, six reinforcing ribs 8 are arranged in a region 9, which followsimmediately after the end 10 of the cap thread 6. Looking in thecircumferential direction U, the region 9 adjoins the end 10 of the capthread 6. Diametrically opposite second reinforcing ribs 18 arearranged. Ten second reinforcing ribs 18 extend through an angularregion of about 150°. The second reinforcing ribs 18 have the samelength L′ in each case (see also FIG. 2).

FIG. 5 shows an enlarged representation of the cut-out C from FIG. 4.The inner faces 11 of the reinforcing ribs 8 follow an imaginerycylindrical face Z. Seen in the circumferential direction U, thereinforcing ribs 8 are arranged towards the end 10 of the cap thread 6.

Of course, other configurations of the reinforcing ribs are alsopossible. For example, it is possible to distribute a plurality ofequally long reinforcing ribs evenly over the circumference of theclosure cap. Moreover, it is conceivable to provide reinforcing ribs,which extend from the cap thread up to the head plate. FIG. 6 arepresents an embodiment, in which a large number of equally longreinforcing ribs 38 are arranged evenly over the whole circumference ofthe closure cap. The length l′of all reinforcing ribs is identical. Thelower end of the reinforcing ribs 6 is arranged above the cap thread 6.Represented schematically in FIG. 6 b are reinforcing ribs 48, whichextend from the lower edge of the cap thread 6 up to the head plate 2.The reinforcing ribs 48 are thereby arranged so that they lie outsidethe thread region used by the mouth thread 26 of the container.

The reinforcing ribs 38, 48 of FIGS. 6 a and 6 b also result in thedesired stiffening between cap skirt 4 and head plate 2.

FIG. 7 shows a further alternative embodiment. The same referencesymbols denote the same parts as in the previous Figures.

The reinforcing ribs 58 extend up to the underside of an outer seal 32.The stop between the container mouth 21 and the closure cap 1 takesplace via a front seal 33.

Second reinforcing ribs 18 are arranged diametrically opposite thereinforcing ribs 58. The reinforcing ribs 18 abut on the start of thethread and thereby likewise have a braking effect. Because of thestiffening ribs 18, 58, any axial force applied in the event ofoverturning in the circumferential direction is evenly distributed.

Although a preferred embodiment of the invention has been specificallyillustrated and described herein, it is to be understood that minorvariations may be made in the apparatus without departing from thespirit and scope of the invention, as defined the appended claims.

1. A closure cap (1) for a container containing a carbonated beveragecomprising an end panel (2) joined at a radius portion (7) to adepending peripheral skirt (4); said end panel (2), radius portion (7)and depending peripheral skirt (4) each including an inner surface; saidradius portion inner surface defining a transition surface between saidend panel inner surface and an uppermost peripheral inner surfaceportion of said peripheral skirt inner surface; a cap thread (6) belowsaid uppermost peripheral inner surface portion of said peripheral skirtinner surface for threading the closure cap (1) to an associatedcontainer mouth, a plurality of peripherally spaced substantially stiffreinforcing rib means (8, 38, 48, 58) for stiffening said peripheralskirt (4) at said uppermost peripheral inner surface portion and saidend panel (2) at said transition surface thereby preventing at least oneof radial outward peripheral skirt bulging and spreading between theperipheral skirt and the end panel; said plurality of reinforcing ribmeans (8, 38, 48, 58) being a plurality of reinforcing ribs extendingaxially from said end panel inner surface along and projecting radiallyinwardly from and beyond said uppermost peripheral skirt inner surfaceand terminating contiguous said cap thread, said cap thread (6) having athread end portion located contiguous said uppermost peripheral innersurface portion, a plane through said thread end portion defining animaginary screwing line (S), said plurality of reinforcing ribs eachhaving a terminal end contiguous said imaginary screwing line (S), andat least some of said reinforcing ribs being of different axial lengths.2. The closure cap as defined in claim 1 wherein said cap thread (6) hasa thread end (10) located contiguous said uppermost peripheral innersurface portion, and said plurality of reinforcing ribs are located in aperipheral region (9) adjacent said thread end (10).
 3. The closure capas defined in claim 1 wherein said cap thread (6) has a thread endportion located contiguous said uppermost peripheral inner surfaceportion, a plane through said thread end portion defines an imaginaryscrewing line (S), and said plurality of reinforcing ribs each have aterminal end contiguous said imaginary screwing line (S).
 4. The closurecap as defined in claim 1 wherein said cap thread (6) has a thread endportion located contiguous said uppermost peripheral inner surfaceportion, a plane through said thread end portion defines an imaginaryscrewing line (S), said plurality of reinforcing ribs each have aterminal end contiguous said imaginary screwing line (S), and at leastone of said reinforcing ribs projects axially downwardly beyond saidimaginary screwing line (S).
 5. The closure cap as defined in claim 1wherein said cap thread (6) has a thread end portion located contiguoussaid uppermost peripheral inner surface portion, a plane through saidthread end portion defines an imaginary screwing line (S), saidplurality of reinforcing ribs each have a terminal end contiguous saidimaginary screwing line (S), and at least one of said reinforcing ribsprojects axially downwardly to but not beyond said imaginary screwingline (S).
 6. The closure cap as defined in claim 1 wherein saidplurality of reinforcing ribs are located in a peripheral region (9) ofsaid uppermost peripheral inner surface portion which extends over anangular section (α) of substantially 90°.
 7. The closure cap as definedin claim 1 wherein said plurality of reinforcing ribs are located in aperipheral region (9) of said uppermost peripheral inner surfaceportion, another plurality of peripherally spaced substantially stiffreinforcing rib means for stiffening said peripheral skirt (4) at saiduppermost peripheral inner surface portion and said end panel (2) atsaid transition surface thereby preventing at least one of radialoutward peripheral skirt bulging and spreading between the peripheralskirt and the end panel; said another plurality of rib means beinganother plurality of reinforcing ribs extending axially from said endpanel inner surface along and projecting radially inwardly beyond saiduppermost peripheral skirt inner surface and terminate contiguous saidcap thread, and said another plurality of reinforcing ribs (18) and saidfirst-mentioned plurality of reinforcing ribs (8, 38, 48, 58) beinglocated at different angular regions of said uppermost peripheral innersurface portion.
 8. The closure cap as defined in claim 1 wherein saidplurality of reinforcing ribs are located in a peripheral region (9) ofsaid uppermost peripheral inner surface portion, another plurality ofperipherally spaced substantially stiff reinforcing rib means forstiffening said peripheral skirt (4) at said uppermost peripheral innersurface portion and said end panel (2) at said transition surfacethereby preventing at least one of radial outward peripheral skirtbulging and spreading between the peripheral skirt and the end panel;said another plurality of rib means being another plurality ofreinforcing ribs extending axially from said end panel inner surfacealong and projecting radially inwardly beyond said uppermost peripheralskirt inner surface and terminate contiguous said cap thread, saidanother plurality of reinforcing ribs (18) and said first-mentionedplurality of reinforcing ribs (8, 38, 48, 58) being located at differentangular regions of said uppermost peripheral inner surface portion, andsaid another plurality of reinforcing ribs each have substantially thesame axial length (l).
 9. The closure cap as defined in claim 1 whereinsaid plurality of reinforcing ribs each project radially inwardly suchthat innermost faces (11) of said plurality of reinforcing ribs lie onan imaginary cylinder (2) corresponding substantially to an outercylindrical surface of an associated container mouth.
 10. The closurecap as defined in claim 2 wherein said plurality of reinforcing ribs arelocated in a peripheral region (9) of said uppermost peripheral innersurface portion which extends over an angular section (α) ofsubstantially 90°.
 11. The closure cap as defined in claim 2 whereinsaid plurality of reinforcing ribs are located in a peripheral region(9) of said uppermost peripheral inner surface portion, anotherplurality of peripherally spaced substantially stiff reinforcing ribmeans for stiffening said peripheral skirt (4) at said uppermostperipheral inner surface portion and said end panel (2) at saidtransition surface thereby preventing at least one of radial outwardperipheral skirt bulging and spreading between the peripheral skirt andthe end panel; said another plurality of rib means being anotherplurality of reinforcing ribs extending axially from said end panelinner surface along and projecting radially inwardly beyond saiduppermost peripheral skirt inner surface and terminate contiguous saidcap thread, and said another plurality of reinforcing ribs (18) and saidfirst-mentioned plurality of reinforcing ribs (8, 38, 48, 58) beinglocated at different angular regions of said uppermost peripheral innersurface portion.
 12. The closure cap as defined in claim 3 wherein saidplurality of reinforcing ribs are located in a peripheral region (9) ofsaid uppermost peripheral inner surface portion which extends over anangular section (α) of substantially 90°.
 13. The closure cap as definedin claim 3 wherein said plurality of reinforcing ribs are located in aperipheral region (9) of said uppermost peripheral inner surfaceportion, another plurality of peripherally spaced substantially stiffreinforcing rib means for stiffening said peripheral skirt (4) at saiduppermost peripheral inner surface portion and said end panel (2) atsaid transition surface thereby preventing at least one of radialoutward peripheral skirt bulging and spreading between the peripheralskirt and the end panel; said another plurality of rib means beinganother plurality of reinforcing ribs extending axially from said endpanel inner surface along and projecting radially inwardly beyond saiduppermost peripheral skirt inner surface and terminate contiguous saidcap thread, and said another plurality of reinforcing ribs (18) and saidfirst-mentioned plurality of reinforcing ribs (8, 38, 48, 58) beinglocated at different angular regions of said uppermost peripheral innersurface portion.
 14. The closure cap as defined in claim 4 wherein saidplurality of reinforcing ribs are located in a peripheral region (9) ofsaid uppermost peripheral inner surface portion which extends over anangular section (α) of substantially 90°.
 15. The closure cap as definedin claim 4 wherein said plurality of reinforcing ribs are located in aperipheral region (9) of said uppermost peripheral inner surfaceportion, another plurality of peripherally spaced substantially stiffreinforcing rib means for stiffening said peripheral skirt (4) at saiduppermost peripheral inner surface portion and said end panel (2) atsaid transition surface thereby preventing at least one of radialoutward peripheral skirt bulging and spreading between the peripheralskirt and the end panel; said another plurality of rib means beinganother plurality of reinforcing ribs extending axially from said endpanel inner surface along and projecting radially inwardly beyond saiduppermost peripheral skirt inner surface and terminate contiguous saidcap thread, and said another plurality of reinforcing ribs (18) and saidfirst-mentioned plurality of reinforcing ribs (8, 38, 48, 58) beinglocated at different angular regions of said uppermost peripheral innersurface portion.
 16. The closure cap as defined in claim 5 wherein saidplurality of reinforcing ribs are located in a peripheral region (9) ofsaid uppermost peripheral inner surface portion which extends over anangular section (α) of substantially 90°.
 17. The closure cap as definedin claim 5 wherein said plurality of reinforcing ribs are located in aperipheral region (9) of said uppermost peripheral inner surfaceportion, another plurality of peripherally spaced substantially stiffreinforcing rib means for stiffening said peripheral skirt (4) at saiduppermost peripheral inner surface portion and said end panel (2) atsaid transition surface thereby preventing at least one of radialoutward peripheral skirt bulging and spreading between the peripheralskirt and the end panel; said another plurality of rib means beinganother plurality of reinforcing ribs extending axially from said endpanel inner surface along and projecting radially inwardly beyond saiduppermost peripheral skirt inner surface and terminate contiguous saidcap thread, and said another plurality of reinforcing ribs (18) and saidfirst-mentioned plurality of reinforcing ribs (8, 38, 48, 58) beinglocated at different angular regions of said uppermost peripheral innersurface portion.
 18. The closure cap as defined in claim 1 wherein saidplurality of reinforcing ribs are located in a peripheral region (9) ofsaid uppermost peripheral inner surface portion which extends over anangular section (α) of substantially 90°.
 19. The closure cap as definedin claim 1 wherein said plurality of reinforcing ribs are located in aperipheral region (9) of said uppermost peripheral inner surfaceportion, another plurality of peripherally spaced substantially stiffreinforcing rib means for stiffening said peripheral skirt (4) at saiduppermost peripheral inner surface portion and said end panel (2) atsaid transition surface thereby preventing at least one of radialoutward peripheral skirt bulging and spreading between the peripheralskirt and the end panel; said another plurality of rib means beinganother plurality of reinforcing ribs extending axially from said endpanel inner surface along and projecting radially inwardly beyond saiduppermost peripheral skirt inner surface and terminate contiguous saidcap thread, and said another plurality of reinforcing ribs (18) and saidfirst-mentioned plurality of reinforcing ribs (8, 38, 48, 58) beinglocated at different angular regions of said uppermost peripheral innersurface portion.